Power driven typewriter



March 7, 1933. H. BENZING I POWER DRIVEN TYPEWRITER Filed Sept. 8, 1931 s Sheets-Sheet 2 IIIVGII/Or Altar/revs Patentecl Mar. 7, 1933- v 7 p UNITED STATES PATENT OFFICE HUGO BENZING, F DBESDEN, GERMANY POWER DRIVEN TYPEWRITEB Application filed September 8, 1931, Serial No. 561,706, and in Germany January 5, 1989.

The present invention relates to powervided on the latter a spring-controlled pawl, driven typewriters, computing machines, etc., which, without consideration to the particuin which the movement of the type levers is lar position of the key bar at that moment, performed through the medium of friction locks the eccentric lever after its return into rods, which are pressed by IOlls against conits initial position. 55

tinuously revolving operating rollers. The arrangement according to the inven- In arrangements of this kind hitherto in tion is not on y extremely simple in form, but use either considerable pressure on the keys also offers the advanta e of very small rehas been required to press the friction rods sistance on the part of t e keys and absolute against the operating rollers, or it has been ensurit of one single, sharp impression.

found necessary to employ cams of a compli- :The lnvention will now be described more cated nature, which cause the movement of fully with reference to the accompanying the type lever upon depression of the key. drawings, in which These known arrangements are 'accom- Fig. 1 is a sectional view taken through a panied by the disadvantage that the same fultypewriter or computing machine of the fil the intended object only to an incomplete usual kind fitted with the novel form of drive degree, or are so sensitive as to be quite unaccording to the invention. a suitable for permanent operation. Figs. 2-4 show the actuating means in It is the object of the present invent-ion to three different positions.

20 overcome the disadvantages in question, and Figs. 5-7 illustrate three different forms this is accomplished by the fact that each of of embodiment of the rods and the operatthe friction rods movin the t pe levers rests in rollers. through the medium 0 an a justable inter- Fig. 8 is a section through a few-key bars mediate lever on an eccentric, which is acted with actuating means according to the line 5 upon by a spring, or is held in its inoperative VIIIVIII in Fig. 9. position by means of a stop, and which is ac- Fig. 9 is a section along the line IX-IX in tuated upon depression of the key and, acting Fig. 8, and

under the influence of the spring, presses the Figs. 10 and 11 show, in two different porod against the continuously revolving opersitions, a device for ensuring proper engageating rollers, which in turn, shortly prior to ment on the part of the rollers.- 8 the striking of the type against the platen, Although in order to facilitate comprereturn the eccentric lever into the initial pohension the invention is described in the folsition, in which the same is retained by the lowing in its application to typewriters, viz., stop moved back in its path of movement by for the operation of the type bars, it will be 35 the upwardly moving key lever. perfectly obvious that the same may also This arrangement is in so far advantabe adapted literally to computing machines, geous, as the actuation of a key causes the or in point of. fact to any other type of mamovement of only one spring-controlled lechine, in which certain parts thereof are opver, said lever rotating a cam which raises erated through the medium of key bars. another lever; the last-mentioned lever Accordingly, in the assumed instance of a brings the tie rods of'the type bars into 'entypewriter, the type bars 2 are mounted in gagement with the operating rollers, which the frame 1 in a segment 3 oscillatory about revolve constantly. Said tie rods move the a shaft 4. In the position of rest the type first-mentioned lever into its original posibars lie on the pad 5. Each type bar 2 is tion irrespective of their own positions and engaged by an intermediate lever 6, theselethe end part of their motion is caused by the vers 6 being oscillatory about the shaft 7 of kinetic energy of the type bars. a comb 8 extending transversely across the In order to preclude possibility of a second machine and engaging by means of. a stud 9 striking action on the part of the type bar in a slot 10 in the lever 2.

upon depression of the key bar there is pro- The intermediate lever '6 is engaged by a tie-rod 11, which may be moved into engagement with two continuously revolving operating rollers 12 and 13 for the purpose of causing the impression of the type. The operating rollers 12 and 13 are mounted in the frame 1 by means of the shafts 14 and 15, which each carry at the one end a gear wheel 16 and 17, the latter being coupled by an intermediate wheel 18, so that these two wheels 16 and 17, and accordingly the rollers 12 and 13, revolve in the same direction. The rollers 12 and 13 may be driven by a motor, or in any other suitable fashion.

The tie-rods 11 each rest on a roll 19, which is rotatable about a bolt 21 on the lever 20. All of the levers are mounted on a shaft 22, which extends transversely across the entire machine and is mounted in slots 23 in the frame 1 so as to be adjustable in height.

The levers 20 each rest with the front end 24 on an eccentric 25, these eccentrics being furnished on levers 26, which are mounted to be loosely rotatable on a shaft 27 also extending over the entire width of the machine. The levers 26 cooperate with the key bars 28, which are capable of oscillation about a shaft 30 on the beam 29, and are acted upon by springs 31, which have the tendency to retain the key bars 28 in their upper position of rest. The key bars 28 are guided with the front ends in the slots 33 of a comb 32.

The key bars 28 possess a recess 34, into which there extend, by means of projections 35, the levers 26. In the resting position of the key bars 28 the projection 35 thrusts firmly against an abutment 36 in the recess 34, a spring 38 connected with the comb 32 at 37 engaging the lever 26 and drawing the same against the abutment 36. On each key bar 28 there 'is mounted by means of a stud 40 in a slot 39, so as to be oscillatory and displaceable, a pawl 41, the one end of which is acted upon by a spring 42 secured at 43 to the key bar 28. The other end of the pawl 41 engages between two projections 44 arranged in the comb 32 and constituting an ficillatory bearing for this end of the pawl The tie rods 11 carry a stop 45, which may be adjustable, and is capable of cooperating with the lever 26. In accordance with Fig. 5, the tie rods 11 may be of rectangular crosssection, in which case they then cooperate with smooth rollers 12 and 13. In Fig. 6 the rods 11a are of prismatic cross-section on the upper side, and engage in corresponding channels 46 in the rollers 12a and 13a. According to Fig. 7 the rods 11]) are of round cross-section, and engage in round grooves 47 in the rollers 12b and 13b.

The operation of the device, as above described is as follows:

Upon depression of a key bar 28 out of the position according to Fig. 2 into that in Fig. 3 the corresponding lever 26 is rocked under the action of the spring 38 towards the left (Fig. 3). In this manner the eccentric 25 lifts the end 24 of the lever 20, and the roll 19 raises the rod11 to such extent that the continuously revolving rollers 12 and 13 are capable of moving into engagement therewith. vThe rollers 12 and 13 thrust the rod 11 towards the rear, so that the same, through the medium of the intermediate lever 6, causes the type bar to strike the platen. When thrusting back the rod 11 the stop returns the lever 26 somewhat beyond its initial position (Fig. 4), so that the key bar 28 is able to return to the position of rest and can hold tightly the lever 26. At the same time the eccentric 25 releases the lever 20, 24, so that the rod 11 is also able to move downwards and out of engagement with the rollers 12 and 13.

This operation as described can onl take place if the key bar 28 is depressed s ortly and sharply. It is possible, however, that the key is held in the depressed position, or for some reason does not immediately return. In this case the type bar would unintentionally strike the platen a number of times. In a typewriter or computing machine it is obvious that the type should move into contact with the platen only once upon each depression of a key. To ensure that this condition does actually apply there is provided the safety pawl 41 on the key bar 28.

When the key bar 28 is depressed, the projection on the pawl 41 moves downwards (Fig. 3), close to the abutment 36, but this does not take place until the projection 35 on the lever 26 has moved beyond this abutment.

If now the key bar is held in the depressed position (Fig. 4), the projection 35, upon the return of the lever 26, lifts, by means of the rod 11, the pawl 41 in the slot 39 in 0p osition to the action of the spring 42, an the pawl 41 snaps behind the projection 35 on the lever 26, so that the same firmly holds this lever 26 despite depressed key bar 28. The tie rod 11 is consequently out of engagement with the rollers 12 and 13, so that a double striking action is wholly out of the question.

In the arrangement as described the rod 11 is held in engagement with the rollers 12 and 13 only for such length of time as the eccentric 25 looks the lever 20, 24. During the latter part of the striking action merely the kinetic energy of the tie rod 11 of the lever 6 and the type bar 2 becomes efiective to complete the stroke of the latter. The time at which the kinetic energy takes effect is accordingly dependent on incidental conditions in the engagement between the eccentric 25 and the lever 24, so that the same varies when writing and will consequently cause uneven strokes.

I To avoid this drawback the lever 20, in

accordance with Figs. 10 and 11, possesses a rearwardly disposed projection or extension 48 having an inclined face 49. The extensions 48 each cooperate with a pawl lever 50, which is mounted to be oscillatory on a shaft 51 extending transversely over the entire machine. The pawl lever 50 possesses a projection 52, and is connected with the boss 54 of the lever 20, 48 by means of a spring 53. The engagement oint 55 of the spring 53 0n the boss 54 is SHOE that the spring 53 has the tendency to rotate the lever 20, 48 about the shaft 22. On the rod 11 there is a second operating member 56, whichis capable of cooperation with the pawl lever 50.

The operation of this device is as follows: If the key bar 28 is depressed, and the roll 19 with the lever 20 lifted by the lever 26, the extension 48 moves downwards. Under the action of the spring 53 the projection 52 moves over the inclined face 49 of the extension 48, and has the tendency to press the roll 19 against the rod 11, to thus hold the latter in proper engagement with the rollers 12 and 13. When the movement of the type has practically been completed the operating member 56 thrusts against the pawl lever 50 and conjointly moves the same. The projection 52 releases the extension 48, and the pull of the spring 53 on the boss 54 causes the lever 20 to spring back into its initial position, so that the rod 11 is immediately moved out of engagement with the ro lers 12 and 13. Bfy reason of this arrangement the initiation o the release of the rods 11 is very exactly defined, even in such cases in which the eccentric 25 has already released the lever 20, 24, as illustrated in Fig. 11.

It will be understood that no restriction is made to the specific form of embodiment shown, that this embodiment is quoted merely to illustrate the possible adaptation of the invention to a typewriter, and that accordingly various modifications are quite possible within the meaning of the above description and the annexed claims without departing from the spirit of the invention.

What I claim as new and desire to secure by Letters Patent is:

1. In a device of the character described, in combination, a continuously rotating ro ler, a plurality of keys, a stop connected'with one of said keys, a lever adapted to come in contact with said stop, a spring connected with said lever, a cam rigidly connected with said lever, another lever associated with said cam, means for adjusting the position of the second-mentioned lever, a roll connected with the second-mentioned lever and movable therewith, a friction rod adapted to be pressed by said roll against said rotating roller, a type bar, and means connecting said type bar with said friction rod.

2. In a device of the character described, vin combination, a continuously rotating roller,

a plurality of keys, a projection forming a part of one of sald keys, a lever adapted to come in contact with said projection, said projection holding said lever when the corresponding key is at rest, a pawl resiliently mounted on sald key, a spring connected with said lever and adapted to move the same after its release from contact with said projection, (said pawl being adapted to come in contact with said lever at a, certain position of said key, a cam connected with said lever and movable therewith, another lever associated with and movable by said cam, a roll connected with the second-mentioned lever and movable therewith, a friction rod adapted to be pressed by said roll against said rotating roller, a type bar, and means connecting said type bar with said friction rod.

3. In a device of the character described, in combination, a machine frame, a continuously rotating roller within said frame, a plurality of keys, pawls resiliently mounted in slots formed in said keys, each key carrying one of said pawls, members forming a part of said frame and projecting between said pawls, springs pressing against said pawls, each spring being in contact with one of said pawls, a lever associated with one of said keys, a spring connected with said lever, a cam connected with said lever and movable therewith, another leverassociated with and movable by said cam, a roll connected with the second-mentioned lever and movable therewith, a friction rod adapted to be pressed by said roll against rotating roller, a type bar, and means connecting said type bar with said friction rod.

4. In a device of the character described, in combination, a machine frame, an operating roller within said frame, a plurality of ioo keys, pawls resiliently mounted in slots formed in said keys, each key carrying one of said pawls, members forming a part of said frame and projecting between said pawls, springs pressing against said pawls, each spring being in contact with one of said pawls, a lever associated with one of sald eys, a spring connected with said lever, a

cam connected with said lever and movable therewith, another lever associated with and movable by said cam, a roll connected with the second-mentioned lever and movable therewith, the second-mentioned lever being one of said keys, a cam connected with said lever and movable therewith, another lever associated with and movable by said cam, a roll connected with the second-mentioned 5 lever, a friction rod adapted to be pressed by said roll against said rotating roller, a t bar, means connecting said' type bar with said friction rod, a spring connected with the first-mentioned lever, a pawl resil- 1 iently mounted on said key, a member forming an extension of the second-mentioned lever, a pawl lever adapted to come in contact with said member, a projection forming a part of said-pawl lever, and a spring connected with said pawl lever.

In testimony whereof I have afiixed my signature.

HUGO BENZING. 

